Dental chair.



PATENTBD AUG. 2,1904.

F. E. CASE.

DENTAL CHAIR.

APPLICATION FILED MAB. 2a, 1904.

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NO MODEL.

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AT TOR N EY No. 766,591. PATENTED AUG. 2, 1904. I. E. CASE.

DENTAL CHAIR.

APPLIOATION HLBD MAR. 28, 1904` No MODEL. s SHEETS-summa.

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MW. ATTORNEY No. 766,591. PATENTED AUG. 2, 1904, F. E. CASE.

DENTAL CHAIR.

APPLICATION FILED MAR. 28, 1904.

N0 MODEL. 3 SHEETS-SHEET 3.

WITNESSES INVENTOH fafa/M Z5. @cr/.JQ

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ATTORNEY Patented August 2, 1904.

UNITED STATES PATENT OFFICE.

FRANK E. CASE, OF CANTON, OHlO.

DENTAL CHAIR.

SPECIFICATION forming part of Letters Patent No. '766.591, dated August2, 1904.

Original application filed August 7, 1903, Serial No. 168,555. Dividedand this application filed March 28, 1904. Serial No. 200,247. (Nomodel.)

To JZ 114mm/ it nul/y concern.-

Be itknown that l, FRANK E. CASE, a citizen of the United States,residing at Canton, in the county of Stark and State of Ohio, haveinvented certain ncw and useful Improvements in Dental Chairs, the samebeing' illustrated and described, but not claimed, in my application forLetters Patent filed August 7, 1903, Serial No. 168,555, of whichapplication this is a divisional part and of which invention thefollowingl is a specification.

The invention relates to arotatable and vertically-extensible base for achair; and the objects of the improvements are to provide a rotatablebase on a Hoor-plate with simple and convenient means for joining andmanipulating the same and to provide a pump which with all its parts inworking order can be readily lifted out of the base. l attain theseobjects by the construction, mechanism, and arrangement illustrated inthe accompanying drawings, in which- Figure l is a perspective verticalsection of the chair-base, showing the pump in place; Fig. 2, aperspective view of the base extended with the pump removed, but showingthe brake-dog in its proper location; Fig. 3, a detached front elevationof the brake-shaft, showing the release-thimble in section thereon; Fig.e, a detached perspective view of the pump; Fig. 5, afragmentaryperspective under view of the forward end of the pump; and Fig. 6 a left side elevation of the brakedog and adjoining' and adjacentparts, partly in section.

Similar numerals refer to similar parts throughout the drawings.

The floor-plate 1 is preferably circular in form, and on its upper sideis provided the annular iange 2, having' the inturned rim 3, under whichrini is formed the groove L1. The base 5 is preferably formed as acylinder with its sides somewhat flattened and is open above and belowand in front. The base terminates The rear part, that is less thanone-half of the base, is extended downward below the external flange,and this extended part T'is provided externally on its rim with theannular tongue 8, which tongue is adapted to cnter and travel around inthe floor-plate groove. 'Vhen the base is placed on the floor-plate, itis first set slightly forward from its proper position, which advancedposition permits the rear depending part to enter inside of the rim ofthe floorplate fiange, after which the base is pushed directly back, sothat the annular tongue enters the annulaigroove in the floorplateiiange.

The box-standard 9 is formed similar in section to the base andtelescoped therein, being provided with the usual vertical grooves, as10, for the corresponding tongues, as 11, formed in the base, and thebodystandard 12 is likewise formed and telescopes in the boxstandard,being provided with the similar grooves, as 13, for the correspondingtongues, as 111, in the box-standard. The body of the chair (not shown)is mounted on the bodystandard, preferably by a horizontal transversepivot, and it is raised and lowered by the elevation and depression ofthe respective standards.

The pump 15 and all its parts in working order is formed entirelyseparate from the floor-plate, the base, and the standards, and it isplaced in the base through the open front side thereof. The pump issupported in the base by the lugs 16, formed near the forward edges onits sides and near the top, the inclined lower edges 17 of which lugsbeing adapted to hook over the bosses 18, which are formed near the topof the forward edges of the base, and the pump is held in position onthese supports by the stay-pin 19, located on the forward part of thebase-liange, which pin enters the corresponding recess 20 in the underside of the pump when the pump is properly placed in the base.

The brake-dog 9.1 is pivoted at 22 on one side of the pump, from whichpivotal point the dog curves downward and forward and terminates belowin the toe23, which is adapted to swing forward into the annular groovein the floor-plate flange and to bind against the rim thereof or to beswung back to free` this contact, as shown in Fig. 6x rI`he upper partof the forward end of the brake-clog is extended over the base-flangeand forms the head 24, in which head is provided the adjustablecontact-screw 25.

The brake-shaft 26 is transversely journaled in the forward part of thelpump, and on the outerfree end of the shaft is formed the brakelever 27,which normally extends forward and slightly upward and has the pedal 28formed on its end. The inner end of the brake-shaft is somewhatflattened on the lower forward side 29, against which fiat side the headof the contact-screw rests when the brake is released. By depressing thebrake-pedal, as by the operators foot, the shaft is rotated to bring itsfully-rounded side against the head of the contact-screw, as shown inFig. 6, whereby the brake-dog is forced forward and its toe is thrustinto the groove and against the rim of the floor-plate flange and actsto brake orstop the base against rotation. The recess 30 is provided inthe upper forward side of the brake-shaft, into which recess isprojected the stop-screw 31, which screw serves the double purpose oflimiting its rotation each way and of stopping it against endwisemovement.

The upper free end of the pump piston-.rod 32 is attached to thebox-standard by means of the bracket 33, which bracket extends throughthe slot 34, which is provided for it in the body-standard. A pulley, as35, is pivoted on each inner side near the top of the boxstandard, andon this pulley is mounted the endless c hain 36. A guide-rib,as 37, isformed in each side of the box-standard directly below the pulley, andthe endless chains operate along each side of these ribs and aroundtheir lower rounded ends. The vertically adjustable bracket 38 isattached in each side of the base at the forward edge near the top, toAwhich bracket the endless chains are attached by bolts or rivets, as 39,at points opposite the top of the base. When both standards are loweredand telescoped in the base, the endless chains are attached to thebottom of the body-standard by thebolts or rivets, as at 40, so thatwhen the box-standard is raised by the piston-rod by the operation ofthe pump the chains being attached to the base and after passing overthe pulleys on the box-standard, being also attached to thebody-standard and its pulleys, will elevate the body-standard at therate of two to one and when the box-standard is permitted to come downby opening the release-valve the bod y-standard also comes down at thissame rate by the positive action teeei of the endless chains passingaround the lower end of the guide-ribs.

In order to remove the pump from the chairbase, it is only necessary todetach the pistonrod from the box-standard bracket, whereupon the pumpand all of its parts in working order can be lifted bodily out ofthebase, and when the pump is in place its exposed side and the attachedparts thereon are preferably arranged to substantially close the openside of the base.

What I claim as my invention, and desire to secure by Letters Patent,is-

l. In a chair, a vfloor-plate having an annular flange with an internalgroove thereon, a base having an external annular flange' resting on thefloor-plate flange with part of one side of the base extended below theexternal flange, an annular tongue on the depending part of the baseadapted to operate in the floor-plate groove, and a brake-dog pivoted onthe opposite side of the base having a toe.

on its free end adapted to be swung to bind against the floor-platetongue.

2. In a chair, a oor-plate having an annular flange with an internalgroove thereon, a base having an external annular flange resting on theHoor-plate flange with part of one side of the base extended below theexternal flange, and an annular tongue on the depending part of the baseadapted to operate in the plate-groove.

3. In a chair, a floor-plate having an annular flange thereon,l arotatable base resting on the flange, a brake-dog pivoted on the baseand having a toe on its free end adapted to be swung to bind against theflange, a shaft journaled in the base having part of-one side flattened,and a screw in the brake-dog normally having its end in contact with theflat side of.

the shaft.

4. In a chair, a hollow base being open on one side and having bosses onthe side edges near the top with an annular flange at the bottom acrossthe side opening there being a stay-pin on the flange, and a pump,adapted to be enteredinto the base through its open side and having lugsnear the outer edges on the sides near the top adapted to hook over thebase-bosses, and a recess in the bottom of the pump near the outer edgeadapted to receive the stay-pin.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

FRANK E. CASE.

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